Motorcycle Brake Systems

  • December 3, 2016 6:35 AM PST

    OK I finally got up the nerve to ask this stupid question........Everybody understands that 70% of your braking power comes from the front brake and 30% from the back brake. 

    OK here is my stupid question, and I know already when I hear the answer I will just hear a big DUD coming from my head.

    Why is it necessary to have two different sources of brake actuation force? Why can't both brakes be actuated at the same time by one force ie .....brake pedel that is now the rear brake.

    If it is safer to actuate the rear brake a split second before the front, that could be accomplished by a sequence valve. 

    I totally understand what happens when you apply to much front or to much rear brake alone as the system is designed now, but why can we have more of a car like brake system.

    I know I can already hear some out there..........."Hell we've being this way for a hundred years"!

    Not trying to change the world of motorcycle braking.........just wondering that's all ?

    Stay Safe

    Night Dragon

    • 10 posts
    December 3, 2016 7:30 AM PST

    I saw a system like that on a sidecar setup from Liberty Sidecars.  The front brake hand control operated both brakes at the same time through an actuator valve. The owner was in a wheel chair and could not use his legs. He through his wheel chair in the sidecar and rode off.  Shift controls were also on the bars ... electronic shifting.

    • 8 posts
    December 3, 2016 9:53 AM PST

     Copyed from Wikipedia 

     

     

    In many countries, including the United States, the law requires a motorcycle to have two separate braking systems.[3] Invariably, the handlebar lever operates the front brake, and the foot pedal operates the rear. Any bike with CBS must still have two separate inputs for braking, even if (as on the Honda VFR1200) each control independently operates both front and rear brakes. By contrast, a car is required to have only one braking system for dynamic braking (i.e. braking when moving), plus a separate parking brake.

    The justification for two separate braking systems is that, compared to cars, a motorcycle has, proportionately, a higher centre of gravity, a shorter wheelbase, a higher power-to-weight ratio, and a smaller tyre contact patch area. All these factors lead to a much greater weight transfer to the front wheel on braking, and a greater risk of skidding.[4] A rider needs to be able to use each brake independently to maintain control, and a CBS system seeks to further reduce any skid risk.

  • December 3, 2016 1:22 PM PST

    [blockquote]NorthIdaho53 said:

     Copyed from Wikipedia 

     

     

    In many countries, including the United States, the law requires a motorcycle to have two separate braking systems.[3] Invariably, the handlebar lever operates the front brake, and the foot pedal operates the rear. Any bike with CBS must still have two separate inputs for braking, even if (as on the Honda VFR1200) each control independently operates both front and rear brakes. By contrast, a car is required to have only one braking system for dynamic braking (i.e. braking when moving), plus a separate parking brake.

    The justification for two separate braking systems is that, compared to cars, a motorcycle has, proportionately, a higher centre of gravity, a shorter wheelbase, a higher power-to-weight ratio, and a smaller tyre contact patch area. All these factors lead to a much greater weight transfer to the front wheel on braking, and a greater risk of skidding.[4] A rider needs to be able to use each brake independently to maintain control, and a CBS system seeks to further reduce any skid risk.

    [/blockquote]

     

     

    Well Steve now that makes sense. Thanks Brother for clearing that up for me.

    Night Dragon

    • 58 posts
    December 3, 2016 11:34 PM PST

    Honda tried that a while back on the Goldwing.  Don't know if they still have it where any brake application (foot or hand) actuated both front and rear.

    • 2 posts
    December 4, 2016 7:27 PM PST
    My 2015 SGS has integrated braking hand or foot controls works both at 25mph or slower.
    • 2 posts
    December 4, 2016 7:32 PM PST
    Sorry... that would be intergraded breaking, works quite well bike has 6 piston Bembo brakes
    • 5417 posts
    December 8, 2016 8:40 AM PST

    Well in addition to the law that NorthIdaho53 mentioned I think it may also be reider preference/demand.  I can think of a number of times I would only want to use one of the brakes or different front to back ration than I normally use.

    i.e.

    On gravel or sand I would not want to use any front brake - trust me I have and it never turned out well.

    On a emergency, fast, stop I always tend to grab more front brake since all the weight is shifting that way and I don't want to tire to break loose.

     

    However with the advances in anti-lock brakes on motorcycles I can possibly see a single brake system being not too far in the future


    This post was edited by Lucky at December 8, 2016 8:42 AM PST
  • December 18, 2016 7:56 AM PST

    Having Both the front & the Back Brakes would really Suck when your trying to break traction on the rear tyre in the dirt while throttling up with the front brake on to make a 180 degree manuver especally if there is a rock or tree in front of you. 

    also using a downshift sequence on throttle using the engine to control the bikes speed slows the rear and you never touch the foot brake while your pulsing the front brake. 

    thirdly. having two entirly seperate systems weather they be cable or hydraulic prevents total failure of braking which could occur if you had just one system. 

    Redundancy is the key.

     

     


    This post was edited by Deleted Member at December 18, 2016 8:00 AM PST
    • 24 posts
    February 22, 2017 5:56 AM PST

    The Honda Goldwing still has the linked brake system. Front lever applies a little rear brake, foot pedal applies a little front brake.

    Seems like a standing burn out would be more difficult with the linked system. Since I'm past my burn out days I haven't tried it. Maybe tomorrow.

    • 5417 posts
    February 24, 2017 10:02 AM PST

    [blockquote]FloridaLarry said:

    The Honda Goldwing still has the linked brake system. Front lever applies a little rear brake, foot pedal applies a little front brake.

    Seems like a standing burn out would be more difficult with the linked system. Since I'm past my burn out days I haven't tried it. Maybe tomorrow.

    [/blockquote]

     

    Completely forgot about the standing burnout.  Another good reason to keep the seperate :-)